Mica-Filled PVC Composites: Effect of Particle Size, Filler Concentration, and Surface Treatment of the Filler, on Mechanical and Electrical Properties of the Composites

Abstract

Polyvinyl chloride (PVC) is one of the most commonly used thermoplastic materials in cables and wires for electrical insulation. PVC has very good-to-excellent electrical and mechanical properties which make it suitable for use as an electrical insulating material in many domestic and industrial electrical insulation applications. Mica-filled PVC composites may become the cost-effective substitutes for other types of cable and wire compositions with their improved properties. In this study, water ground mica samples of different particle sizes, surface areas, and concentrations were used for fabrication of PVC composites with and without its surface treatment. Haake Rheochord 9000 compounder using roller-type blades was used for the fabrication of different PVC test composites. Melt-compounded composite was compression molded for making sheets. Mechanical and electrical properties were determined using these test sheets. Mechanical properties such as Young’s modulus, stiffness, and shore hardness increased with increase in mica concentration, whereas tensile strength and elongation at break values are found to decrease with increase in mica concentration. Dielectric properties also increase with mica loading. Morphological studies revealed that there was good adhesion and dispersion of the mica in the PVC composite. It was revealed that mechanical and electrical properties were marginally improved with the use of silane-treated mica.